676 GEOLOGY OF OLD HAMPSHIRE COUNTY, MASS, 



the hig'li-water stand of the flood time and the present flood plain of the 

 river; and this observation may be made over all the area I have been 

 describing in this section south of the old waterfall at the Lily Pond in Gill. 

 (See PL XXII, p. 725.) This indicates a very sudden shrinkage of the 

 waters from their maximum to nearly their jiresent volume. 



I have had occasion already to speak of the depression south of Col- 

 lege Hill, among the drumlins, and of the more extended and much deeper 

 depressions west of South Amherst, and to some extent, also, of the still 

 larger depression of the East Street basin. (See p. 641.) 



The best point from which to study this basin is at the highest part of 

 the road going north from East Street village. One looks across to the 

 massive terrace which flanks the Pelham Hills and sees at his feet the heavy 

 sand bars which had been carried south at the base of the hill on which 

 he stands before the current was cut off by the delta of Cushmans Brook, 

 which stretches in plain sight across the north end of the basin. The face 

 of the high terrace opposite is cut by a series of finely preserved terraces, 

 which seem to have been formed while the East Street Lake was being 

 slowly drained by the gradual lowering- of its outlet, I'ort River, in its 

 course tlrrough the tangle of driimlins south of College Hill by which it 

 reaches the main valley. These teiTaces are figured by President Hitch- 

 cock.^ The sands were carried out in force over the lake bottom nearly as 

 far south as the village, and from this point south the lake bottom is made 

 up of clay, with often less than 3 feet of fine sand covering it, and this 

 forms the lake bottom south across the low extensive Lawrence Swamp, 

 which is, as it were, the reiunant of the old lake imperfectly di*ained by the 

 single outlet of the basin, Fort River. 



In its southern portion the abundant sands around Dwight's station and 

 along the northern flank of Mount Holyoke have been carried down and 

 spread out over the clays by undertow, and slope gradually from the high- 

 water liue out into the basin, and this is the case along the whole north 

 flank of Holyoke. 



Beyond the great oxbow region of the Northampton Meadows, the lake 

 bottom across Southampton, Westfield, and Southwick, except where it has 

 been removed by the basin of Westfield River, is well preserved, and is in 

 eff'ect the deep-water channel, or channels, of the broad arm of the flood 



' Surface Geology, PI. IX, fig. 2. 



